While WWI has traditionally been seen as a turning point in the history of psychiatry, relatively few studies have focused on the impact of the war on civilian lunatic asylums. This paper seeks to contribute to this growing literature by focusing on the management of the Lancashire asylums, at Lancaster (1816), Rainhill, Prestwich (both opened in 1851), Whittingham (1873) and Winwick (1902) following Great Britain’s declaration of war against Germany on 4 August 1914. Primarily based upon an analysis of reports from the five asylums, the Lancashire Asylums Board, the Board of Control, excerpts taken from casebooks and the contemporary press, this paper demonstrates how the international crisis arguably both induced and accelerated changes that were already underway in the management and care of the patients as well as the medical staff’s working conditions. As the asylum at Winwick was taken over as a War Hospital in 1915, followed by the Whittingham asylum in 1917, hundreds of patients were transferred to the other Lancashire asylums. The transfer of new patients in already crowded institutions and in a context of major shortages in staff and material goods profoundly altered life at the asylums during the war. The extent to which the aftermath of the war also heralded “a new era” will be analysed, with a focus on the attendants' working conditions and the major controversy brought about by the publication of Montagu Lomax’s seminal study The Experiences of an Asylum Doctor (1921) based on his years at Prestwich.